Catholic bishops from around the world are calling for an end to fossil fuel use and increased efforts to secure a global climate treaty.
Catholics, they say, should engage with the process leading to a proposed new deal to be signed in Paris next year.
The statement is the first time that senior church figures from every continent have issued such a call.
Negotiators in Lima are currently trying to advance the outline text of an agreement at UN-led talks.
With 1.2bn people worldwide calling themselves Catholic, the church has considerable potential to influence public debate on any issue.
On climate change, some bishops have previously called for rapid decarbonisation and argued for moves to protect the most vulnerable.
But this is first time that such a global collection of senior priests have made such a call.
In their statement, the bishops say they want a “deepening of the discourse at the COP20 in Lima, to ensure concrete decisions are taken at COP21 to overcome the climate challenge and to set us on new sustainable pathways”.